This invention relates generally to a vehicle door cinching method and apparatus for assisting the final closing motion of a sliding vehicle door.
As shown in FIGS. 1 and 2, a typical van-type vehicle has a sliding side door. Upper and lower door tracks define a door path that guides the rear to front closing action and front to rear opening action of known sliding doors. The tracks are substantially straight over most of their length, causing the door to move essentially parallel to the body side over most of the door path. The tracks curve sharply inwardly at their respective ends defining a cinching portion of the door path. A center track may also be included to help guide the door during opening and closing.
A typical cable-type closer/opener drives the door through its fore and aft motion along the door path. The cinching portion of the door path causes the door to tilt inwardly in a final closing or cinching motion. As the door moves to its final closed position within a complementary vehicle door frame, the rear or trailing edge of the door tips inwardly and is then driven inward in a motion generally parallel to an inward-facing surface of a C pillar of the door frame. The rear edge continues to move inward along the cinching portion of the door path until an outer surface of the door and an outer surface of the body side panel are generally flush with one another and the door is latched in place.
The final closing action along the cinching portion of the door path typically involves less than an inch of travel. While the final closing motion along the cinching portion of the door path covers only a short distance, it""s this final motion that both compresses a weather strip between the door and the frame and latches fork bolt type locks that mechanically hold the door in it""s fully closed position. Consequently, the final cinching motion requires more force than what""s required to slide the door fore and aft along the door path.
While some systems rely on the cable closer to provide the final closing or cinching force, many systems provide a separate and independent power cinching apparatus. Incorporation of a separate cinching apparatus allows the power opener/closer that moves the door fore and aft to be sized smaller.
Independent power cinchers typically include a powered fork boltxe2x80x94a somewhat complex mechanism that requires electrical power to unlatch. Because known powered fork bolt cinchers require electrical power to unlatch they also require that a separate manual release be incorporated into the latch to, in the event of power failure, cause the latch to release and allow the door to be opened.
What is needed is a vehicle door cinching apparatus and method that doesn""t require electrical power to release a door that has been cinched into its fully closed position.
According to the invention, a vehicle door cinching apparatus is provided for assisting the final closing motion of a sliding vehicle door. The apparatus includes an electromagnet configured to mount on either an outer periphery of a vehicle sliding door or an inner periphery of a vehicle sliding door frame that""s shaped to receive the sliding door as the door moves along a final inward cinching portion of a door path to a final closed position within the door frame. A ferrous metal plate is configured to be supported on the other of the outer periphery of the door and the inner periphery of the door frame in a position where the plate is removably magnetically engageable with the electromagnet when the door is disposed along the final cinching portion of the door path. Whichever of the plate and electromagnet is supported on the inner periphery of the door frame is supported for lateral movement in a direction generally parallel to the cinching portion of the door path. A cinch drive is operatively coupled to and configured to drive the lateral movement of whichever of the electromagnet and plate is supported on the inner periphery of the door frame thereby driving the door along the final cinching portion of the door path and into the final closed position when the electromagnet is magnetically connected to the plate. A controller is coupled to the electromagnet and is configured to de-energize the electromagnet and release an engaged door from the cinching apparatus once the door has reached its fully closed position.
The invention also includes a method for assisting the final closing motion of a sliding vehicle door. According to this method one the final closing motion of a sliding vehicle door is assisted by connecting a cinching apparatus to the door when the door reaches a final cinching portion of its door closing path. The cinching apparatus is then operated to move the door to its fully closed position where a separate door latch engages to hold the door in its fully closed position. The cinching apparatus is then operated to release the door.
Because the controller de-energizes the electromagnet once the door has been latched in the fully closed position, no electrical power is required to release the cinching mechanism. This obviates the need for the cincher to include a manual release to open the door in case of a vehicle power failure.